A semiconductor memory device may be a storage device which stores data and reads the stored data as needed. Semiconductor memory devices may generally be classified as a random access memory (RAM) or a read only memory (ROM).
The RAM is typically a volatile memory device that loses stored data in the absence of applied power. The ROM is typically a nonvolatile memory device that retains stored data even when applied power is interrupted. Types of RAM include dynamic RAM (DRAM), static RAM (SRAM), and the like. Types of ROM include programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) including flash memory, and the like.
Semiconductor memory devices output data to external circuits using an output driver. Output drivers are usually connected to the external circuits via an output pad. Output pads are generally well-understood elements that may be implemented using a variety of designs.
This Discussion of the Background section is for background information only. The statements in this Discussion of the Background are not an admission that the subject matter disclosed in this section constitutes a prior art to the present disclosure, and no part of this section may be used as an admission that any part of this application, including this Discussion of the Background section, constitutes prior art to the present disclosure.